Wind erosion is a typical issue for stone carvings in northwest China caves, and windbreaks such as shelterbelts have proven to be effective in mitigating wind erosion. This study has the main purpose of examining the effect of shelterbelts on alleviating the wind erosion degree of stone carvings. The applicability of the canopy model for reproducing the aerodynamic effects based on the realizable k–ε and LES model was examined by using a validation metric. The shelterbelt structure has been discussed with the goal of finding the optimum canopy structure to provide a guideline for designing shelterbelts. Compared with the LES model, the realizable k–ε model was adopted in this study based on its comprehensive performance. The results show that a canopy with porosity of φ = 30% and a width of 0.3 to 0.5 H has better sheltering efficiency. Compared to the case with no shelterbelt, the wind speed amplification coefficient decreased by 43%, and the significant decrease in the value of the wind speed amplification coefficient in the primary-harm wind direction demonstrates the effectiveness of the shelterbelt. By exploring preventive protection technology in the context of historical stone carving, this study can promote the practice of scientific and technological protection of cultural relics.

Windy weather frequently occurs in Northwest China, and wind erosion is a typical issue for stone carvings in the caves. In the present study, computational fluid dynamics (CFD) simulations relying on steady 3D Reynolds-averaged Navier-Stokes (RANS) equations were used to simulate the spatial wind field over complex terrain with field measurement validation. This study has the following two aims: (1) to evaluate the accuracy of wind fields simulations with the Interpolated Multiscale Profile (IMP) method over complex terrain; and (2) to provide spatial wind field data of Xumishan Grotto Zone under neutrally stratified atmospheric boundary layer (ABL) over complex terrain. Unmanned aerial vehicle (UAV) oblique photogrammetry and multirotor UAV technology provide application scenarios for the establishment of a high-precision digital model and the determination of accurate inlet boundary conditions. By compiling user-defined functions (UDF) and using the block interpolation method, this method addresses the overestimation of the inlet wind velocity caused by the large elevation difference of the inlet over complex terrain. The results show that the 3D steady RANS simulation based on the IMP method can reasonably and accurately simulate spatial wind fields over complex terrain. This study also provides spatial wind fields data for addressing stone carving erosion caused by strong winds in semi-open Grottoes.

The canyon hilly terrain of northwestern China significantly influences wind field characteristics within the grotto zone, consequently affecting the degree of wind erosion on grotto heritage. In the present study, computational fluid dynamics (CFD) numerical simulations were employed to investigate the effects of mountain length, slope, and spacing on the wind field characteristics of a typically canyon hilly terrain, with the Xumishan Grottoes as a case study. The results show a significant wind speed acceleration at canyon entrances and summits. Variations in mountain length and slope non-linearly affect wind field distribution, with wind speeds at the side and summit stabilizing when the mountain length exceeds three times the mountain height (L ≥ 3H). Based on the simulation results, an improved acceleration ratio formula incorporating mountain length, slope, and spacing was proposed, which demonstrated a discrepancy of only 9.05% compared with the field-validated CFD results for Cave 5 at Xumishan. This study elucidates the wind field formation mechanisms in canyon hilly terrain and provides a scientific basis for addressing the stone carving erosion of grotto heritage, contributing to the advancement of preventive conservation strategies for grottoes in complex terrains.

Carbon sinks have been widely recognized as critical components of climate change mitigation and achieving carbon neutrality. With rapid urbanization, protecting and optimizing urban carbon sinks remain major challenges. This study uses Zhengzhou as a case study and analyzes 2000–2023 land-use data with the InVEST model to quantify carbon stocks and identify high-value carbon-sink areas. Circuit theory was further integrated to delineate ecological security patterns and inform optimization strategies. The results show a net decrease of 19.12 × 10⁶ t in carbon storage from 2000 to 2023, with the most rapid decline occurring during 2015–2020. Spatially, high-value carbon storage clustered in forested, high-elevation areas in the southwest, whereas low values predominated in the urban core. Carbon-sink source areas continued to shrink: fragmentation increased in the east, the west remained relatively stable, and the central area was highly fragmented. Corridor analysis indicated that the mean corridor length first increased and then decreased, accompanied by an expansion of pinch points and barrier areas. The study developed a systematic optimization framework that establishes a “Two Cores, Five Carbon-Sink Areas, Multiple Corridors” security pattern and proposes targeted conservation measures. The proposed methodology and findings offer a transferable basis for managing urban carbon sinks in rapidly developing regions and support both ecological security and climate-change mitigation, promoting sustainable urban development.

Grotto sites are often located in complex terrain such as cliffs, terraces, or river valleys, where the wind field within these grotto areas is influenced by the complex topography. This study develops and evaluates a CFD-based workflow that integrates UAV oblique photogrammetry, three-dimensional terrain reconstruction, field measurements, and steady-state Reynolds-averaged Navier–Stokes (RANS) simulation to investigate the local wind field of the Xumishan Grottoes, China, under neutral atmospheric stratification. This research aims to achieve two objectives: (1) to construct a high-precision digital model of the complex terrain for the numerical simulation process using UAV technology; and (2) to conduct a numerical simulation study of the local-scale spatial wind field over complex terrain under neutral atmospheric stratification conditions, with the wind field within the Xumishan Grotto area as the research subject. The data show that the simulated wind speed ratio and wind direction obtained using the numerical method closely match the measured values, with an average relative error of less than 20%. These results indicate that the UAV-derived terrain-to-CFD workflow can reproduce the dominant spatial pattern of local wind exposure under the tested conditions and provide useful information for identifying wind-sensitive grotto areas, prioritising field monitoring, assessing potential wind-erosion risks, and supporting preventive conservation planning.